Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02C—GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
  • F02C7/00—Features, components parts, details or accessories, not provided for in, or of interest apart form groups F02C1/00 - F02C6/00; Air intakes for jet-propulsion plants
  • F02C7/36—Power transmission arrangements between the different shafts of the gas turbine plant, or between the gas-turbine plant and the power user
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02C—GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
  • F02C3/00—Gas-turbine plants characterised by the use of combustion products as the working fluid
  • F02C3/04—Gas-turbine plants characterised by the use of combustion products as the working fluid having a turbine driving a compressor
  • F02C3/06—Gas-turbine plants characterised by the use of combustion products as the working fluid having a turbine driving a compressor the compressor comprising only axial stages
  • F02C3/067—Gas-turbine plants characterised by the use of combustion products as the working fluid having a turbine driving a compressor the compressor comprising only axial stages having counter-rotating rotors
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02C—GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
  • F02C3/00—Gas-turbine plants characterised by the use of combustion products as the working fluid
  • F02C3/04—Gas-turbine plants characterised by the use of combustion products as the working fluid having a turbine driving a compressor
  • F02C3/107—Gas-turbine plants characterised by the use of combustion products as the working fluid having a turbine driving a compressor with two or more rotors connected by power transmission
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02K—JET-PROPULSION PLANTS
  • F02K3/00—Plants including a gas turbine driving a compressor or a ducted fan
  • F02K3/02—Plants including a gas turbine driving a compressor or a ducted fan in which part of the working fluid by-passes the turbine and combustion chamber
  • F02K3/04—Plants including a gas turbine driving a compressor or a ducted fan in which part of the working fluid by-passes the turbine and combustion chamber the plant including ducted fans, i.e. fans with high volume, low pressure outputs, for augmenting the jet thrust, e.g. of double-flow type
  • F02K3/06—Plants including a gas turbine driving a compressor or a ducted fan in which part of the working fluid by-passes the turbine and combustion chamber the plant including ducted fans, i.e. fans with high volume, low pressure outputs, for augmenting the jet thrust, e.g. of double-flow type with front fan
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02K—JET-PROPULSION PLANTS
  • F02K3/00—Plants including a gas turbine driving a compressor or a ducted fan
  • F02K3/02—Plants including a gas turbine driving a compressor or a ducted fan in which part of the working fluid by-passes the turbine and combustion chamber
  • F02K3/04—Plants including a gas turbine driving a compressor or a ducted fan in which part of the working fluid by-passes the turbine and combustion chamber the plant including ducted fans, i.e. fans with high volume, low pressure outputs, for augmenting the jet thrust, e.g. of double-flow type
  • F02K3/072—Plants including a gas turbine driving a compressor or a ducted fan in which part of the working fluid by-passes the turbine and combustion chamber the plant including ducted fans, i.e. fans with high volume, low pressure outputs, for augmenting the jet thrust, e.g. of double-flow type with counter-rotating, e.g. fan rotors
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
  • F05D2260/00—Function
  • F05D2260/40—Transmission of power
  • F05D2260/403—Transmission of power through the shape of the drive components
  • F05D2260/4031—Transmission of power through the shape of the drive components as in toothed gearing
  • F05D2260/40311—Transmission of power through the shape of the drive components as in toothed gearing of the epicyclical, planetary or differential type
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T50/00—Aeronautics or air transport
  • Y02T50/60—Efficient propulsion technologies, e.g. for aircraft

Definitions

• a gas turbine engine includes a fan section, a compressor section, a combustor section, and a turbine section.
• the fan section drives air along a bypass flowpath while the compressor section drives air along a core flowpath for compression and communication into the combustor section then expansion through the turbine section
• the engine typically includes a low speed shaft and a high speed shaft mounted for rotation about an engine central longitudinal axis relative to an engine static structure via several bearing systems.
• the high speed shaft interconnects a high pressure compressor and high pressure turbine.
• the low speed shaft interconnects a fan, a low pressure compressor, and a low pressure turbine.
• the low speed shaft is connected to the fan through a geared architecture to drive the fan at a lower speed than the low speed shaft.
• the low pressure compressor is positioned aft or rearward of the geared architecture.
• An example engine configuration having this low pressure compressor position is found in United States Patent No. 8,176,725.
• the core airflow is compressed by the low pressure compressor then the high pressure compressor, mixed and burned with fuel in a combustor, then expanded over the high pressure turbine and low pressure turbine.
• the turbines rotationally drive the respective low speed and high speed shafts in response to the expansion.
• This typical arrangement provides a geared turbofan of significant length. In certain applications shorter engine lengths are needed.
• a gas turbine engine has a fan section including a fan hub supporting a plurality of fan blades for rotation relative to a fan case.
• a shaft is rotatable relative to the fan case about an engine center axis.
• a geared architecture is driven by the shaft and provides driving output to rotate the fan hub.
• a compressor is positioned forward of the geared architecture and radially inward of the fan blades, the compressor being driven by the shaft.
• the compressor includes a rotor.
• the shaft directly drives the rotor.
• the compressor comprises a low pressure compressor having a plurality of blades fixed for rotation with the shaft and a plurality of vanes fixed to the fan hub.
• the low pressure compressor is comprised of a plurality of stages.
• the compressor includes a rotor directly driven by the shaft.
• the plurality of stages comprises at least a first stage having a first set of blades directly coupled to the shaft and a first set of vanes mounted to the fan hub, and a second stage having a second set of blades mounted to the rotor and a second set of vanes mounted to the fan hub.
• the vanes rotate with the fan hub in one direction while the blades rotate with the shaft in an opposite direction.
• At least one inter-shaft bearing is mounted between the shaft and a set of vanes to support the vanes for rotation relative to the shaft.
• a static structure and at least one fan support bearing supports the fan hub for rotation relative to the static structure.
• the geared architecture is comprised of a sun gear that is driven by the shaft.
• a plurality of star gears is supported by a carrier fixed to the static structure and in meshing engagement with the sun gear, and an outer annular gear in meshing engagement with the star gears.
• the fan hub includes a plurality of fan drive struts.
• the outer annular gear provides driving input to the fan drive struts.
• a second bearing is positioned radially between the fan hub and the static structure, and is positioned forward of the first bearing.
• the fan section includes a plurality of static vanes extending between the fan case and the static structure.
• the compressor includes a rotor that is directly driven by the shaft.
• the compressor includes a first stage with a first set of blades fixed to a forward end of the shaft and a first set of vanes mounted to the fan hub, a second stage aft of the first stage and including a second set of blades mounted to the rotor and a second set of vanes mounted to the fan hub, and a third stage aft of the second stage and including a third set of blades mounted to the rotor.
• a gas turbine engine has a fan section including a fan outer case, a static structure positioned radially inward of the fan outer case, and a fan hub supporting a plurality of fan blades for rotation relative to the static structure. At least one fan support bearing supports the fan hub for rotation relative to the static structure.
• a shaft is rotatable relative to the static structure about an engine center axis.
• a geared architecture is driven by the shaft and provides driving output to rotate the fan hub.
• a low pressure compressor is positioned forward of the geared architecture and radially inward of the fan blades. The compressor is driven directly by the shaft.
• the geared architecture is comprised of a sun gear that is driven by the shaft.
• a plurality of star gears is supported by a carrier fixed to the static structure and in meshing engagement with the sun gear, and an outer annular gear in meshing engagement with the star gears to drive the fan hub.
• the fan hub includes a plurality of fan drive struts.
• the outer annular gear is drivingly engaged with the fan drive struts.
• the at least one fan support bearing comprises at least a first bearing positioned radially between the fan drive struts and the static structure and a second bearing positioned radially between the fan hub and the static structure.
• the second bearing is located axially forward of the first bearing.
• the first bearing comprises a roller bearing and the second bearing comprises a ball bearing.
• the low pressure compressor is comprised of at least one stage having a set of blades driven by the shaft and a set of vanes positioned aft of the set of blades. The vanes rotate with the fan hub in one direction while the blades rotate with the shaft in an opposite direction.
• At least one inter- shaft bearing is mounted between the shaft and set of vanes to support the vanes for rotation relative to the shaft.
• Figure 1 schematically illustrates a fan section and low pressure compressor of a gas turbine engine.
• Figure 2 schematically illustrates a high pressure compressor, combustor and turbine section of the gas turbine engine.
• FIGS 1-2 schematically illustrate a gas turbine engine 20.
• the gas turbine engine 20 is disclosed herein as a two-spool turbofan that generally incorporates a fan section 22, a compressor section 24, a combustor section 26 and a turbine section 28.
• Alternative engines might include an augmentor section (not shown) among other systems or features.
• the fan section 22 drives air along a bypass flowpath B while the compressor section 24 drives air along a core flowpath C for compression and communication into the combustor section 26 then expansion through the turbine section 28.
• FIG. 1-2 schematically illustrate a gas turbine engine 20.
• the gas turbine engine 20 is disclosed herein as a two-spool turbofan that generally incorporates a fan section 22, a compressor section 24, a combustor section 26 and a turbine section 28.
• Alternative engines might include an augmentor section (not shown) among other systems or features.
• the fan section 22 drives air along a bypass flowpath B while the compressor section 24 drives air along a core flowpath C for compression and communication into the comb
• the engine 20 generally includes a low speed spool 30 and a high speed spool 32 mounted for rotation about an engine central longitudinal axis A relative to an engine static structure 36 via several bearing systems 38. It should be understood that various bearing systems 38 at various locations may alternatively or additionally be provided.
• the low speed spool 30 generally includes an inner shaft 40 that interconnects a low pressure (or first) compressor section 44 and a low pressure (or first) turbine section 46.
• the fan section 22 includes a fan 42 that is driven by the inner shaft 40 through a geared architecture 48.
• the high speed spool 32 includes an outer shaft 50 that interconnects a high pressure (or second) compressor section 52 and high pressure (or second) turbine section 54.
• a combustor 56 is arranged between the high pressure compressor 52 and the high pressure turbine 54.
• a mid-turbine frame 57 of the engine static structure 36 is arranged generally between the high pressure turbine 54 and the low pressure turbine 46.
• the mid-turbine frame 57 supports one or more bearing systems 38 in the turbine section 28.
• the inner shaft 40 and the outer shaft 50 are concentric and rotate via bearing systems 38 about the engine central longitudinal axis A, which is collinear with their longitudinal axes.
• a "high pressure" compressor or turbine experiences a higher pressure than a corresponding "low pressure” compressor or turbine.
• the core airflow C is compressed by the low pressure compressor 44 then the high pressure compressor 52, mixed and burned with fuel in the combustor 56, then expanded over the high pressure turbine 54 and low pressure turbine 46.
• the mid-turbine frame 57 includes airfoils 59 which are in the core airflow path.
• the turbines 46, 54 rotationally drive the respective low speed spool 30 and high speed spool 32 in response to the expansion.
• the engine 20 in one example is a high-bypass geared aircraft engine.
• the engine 20 bypass ratio is greater than about six (6), with an example embodiment being greater than ten (10)
• the geared architecture 48 is an epicyclic gear train, such as a star gear system or other gear system, with a gear reduction ratio of greater than about 2.3 and the low pressure turbine 46 has a pressure ratio that is greater than about 5.
• the engine 20 bypass ratio is greater than about ten (10:1)
• the fan diameter is significantly larger than that of the low pressure compressor 44
• the low pressure turbine 46 has a pressure ratio that is greater than about 5:1.
• Low pressure turbine 46 pressure ratio is pressure measured prior to inlet of low pressure turbine 46 as related to the pressure at the outlet of the low pressure turbine 46 prior to an exhaust nozzle. It should be understood, however, that the above parameters are only exemplary of one embodiment of a geared architecture engine and that the present invention is applicable to other gas turbine engines including direct drive turbofans. [0032] A significant amount of thrust is provided by the bypass flow B due to the high bypass ratio.
• the fan section 22 of the engine 20 is designed for a particular flight condition - typically cruise at about 0.8 Mach and about 35,000 feet.
• “Fan pressure ratio” is the pressure ratio across the fan blade alone, without a Fan Exit Guide Vane (“FEGV”) system.
• the low fan pressure ratio as disclosed herein according to one non- limiting embodiment is less than about 1.45.
• “Low corrected fan tip speed” is the actual fan tip speed in ft/sec divided by an industry standard temperature correction of [(Tambient deg R) / 518.7) ⁇ 0.5].
• the "Low corrected fan tip speed” as disclosed herein according to one non-limiting embodiment is less than about 1150 ft / second.
• the fan section 22 includes a fan hub 60 supporting a plurality of fan blades 62 for rotation relative to a fan case 64.
• the geared architecture 48 is driven by the inner shaft 40 and provides driving output to rotate the fan hub 60 such that the fan hub 60 rotates at a slower speed than the inner shaft 40.
• the gear ratio between the shaft and the fan is approximately 3: 1 ; however, other ratios could also be used.
• the low pressure compressor 44 has a rotor 66 that is positioned forward of the geared architecture 48. The rotor 66 receives driving input from the inner shaft 40.
• the low pressure compressor 44 is comprised of a plurality of stages 68a, 68b, 68c with each stage of the first 68a and second 68b stages including a set of blades 70 and a set of vanes 72 positioned aft of an associated set of blades 70.
• the third stage 68c only includes a set of blades; however, a third set of vanes 72 could also be utilized with the third stage 68c if needed.
• the set of blades 70 of the first stage 68a are coupled directly to the inner shaft 40.
• the sets of blades 70 of the second 68b and third 68c stages are fixed for rotation with the rotor 66.
• the low pressure compressor 44 has three stages; however, it should be understood that the low pressure compressor 44 could have fewer or additional stages than that which is shown.
• the blades 70 are fixed for rotation with the inner shaft 40 and the vanes 72 are fixed to the fan hub 60. As such, the vanes 72 rotate with the fan hub 60 in one direction while the rotor 66 and blades 70 rotate with the inner shaft 40 in opposite direction. Further, as the fan hub 60 is driven through the geared architecture 48, the vanes 72 and fan hub 60 rotate at a slower speed than the inner shaft 40, rotor 66, and blades 70.
• the bearing system 38 includes at least one inter-shaft bearing 74 that is mounted between the inner shaft 40 and one set of the vanes 72 to provide additional support for the vanes 72 as the shaft 40 and vanes 72 rotate relative to each other.
• the inter-shaft bearing 74 supports the vanes 72 of the first stage 68a, i.e. the stage that is foremost located within the engine 20.
• the inter-shaft bearing 74 is radially aligned with the fan blades 62.
• the inner shaft 40 has an increased diameter portion 76 at a forward end 78 of the inner shaft 40.
• the set of blades 70 for the first stage 68a are directly mounted for rotation with the inner shaft 40 at the increased diameter portion 76.
• the inter-shaft bearing 74 is positioned aft of these blades 70.
• the rotor 66 that supports the blades 70 for the second 68b and third 68c stages is positioned aft of the inter-shaft bearing 74.
• the engine 20 includes a static structure 80 and one or more fan support bearings 82 that support the fan hub 60 for rotation relative to the static structure 80.
• the geared architecture 48 is comprised of a sun gear 84 that is driven by the inner shaft 40 and a plurality of star gears 86 that are supported by a carrier that is fixed to the static structure 80.
• the star gears 86 are in meshing engagement with the sun gear 84 and an outer annular gear 90 is in meshing engagement with the star gears 86.
• the inner shaft 40 directly drives the sun gear 84 and the outer annular gear 90 provides driving output to the fan hub 60.
• the fan hub 60 includes a plurality of fan drive struts 92.
• the fan hub 60 includes a forward end 94 and an aft end 96.
• the fan blades 62 are fixed to the forward end 94 and extend radially outwardly toward the fan case 64.
• the fan drive struts 92 are fixed to the aft end 96 and extend radially inwardly toward the engine center axis A.
• the outer annular gear 90 provides direct driving input to the fan drive struts 92.
• the at least one fan support bearing 82 comprises at least a first bearing 82a positioned radially between the fan drive struts 92 and the static structure 80, and a second bearing 82b positioned radially between the fan hub 60 and the static structure 80.
• the second bearing 82b is positioned forward of the first bearing 82a.
• the second bearing 82b is radially aligned with the second stage 68b of the low pressure compressor 44.
• the second bearing 82b is positioned axially between the inter-shaft bearing 74 and the first bearing 82a.
• the first bearing 82a comprises a roller bearing and the second bearing 82b comprises a ball bearing.
• the fan section 22 also includes a plurality of static vanes 100 extending between the fan case 64 and the static structure 80.
• the static vanes 100 are positioned immediately aft of the fan blades 62.
• the overall length of the geared turbofan engine can be reduced.
• the low pressure compressor rotor 66 is not geared and thus rotates substantially faster and in the opposite direction of the geared fan 42.
• the core (inner) flow path C includes a forward located, counter rotating low pressure compressor 44.
• the low pressure compressor vanes 72 are connected to the fan hub 60 and thus rotate with the geared fan 42 in the opposite direction in which the fan blades 70 rotate.
• the fan 42 is driven by the struts 92 that comprise part of the low pressure compressor flow path.
• the amount of compression per stage (blade/vane) is greater than conventional engines in which the vanes are stationary.
• the increase in compression per stage fewer stages are needed in comparison to conventional engines to achieve the same amount of compression.
• the number of engine parts is correspondingly reduced, which enables the engine to be lighter and shorter in overall axial length, as compared to conventional engines.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)

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Citations (9)

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• 2012
  • 2012-07-24 US US13/556,496 patent/US9228535B2/en not_active Expired - Fee Related
• 2013
  • 2013-07-19 CA CA2879756A patent/CA2879756C/en active Active
  • 2013-07-19 EP EP13822304.5A patent/EP2877725B1/en active Active
  • 2013-07-19 WO PCT/US2013/051184 patent/WO2014018382A1/en active Application Filing
  • 2013-07-19 BR BR112015001425-9A patent/BR112015001425B1/pt active IP Right Grant
  • 2013-07-19 RU RU2015106429A patent/RU2665572C2/ru active
• 2015
  • 2015-11-24 US US14/950,095 patent/US10125694B2/en active Active

Patent Citations (9)

Non-Patent Citations (1)

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